1. Field of the Invention
The present invention relates to an occupant protection apparatus, and particularly to a side airbag device that is deployed in the event of a vehicle side impact and a seat belt device.
2. Description of Related Art
In the related art, when a vehicle is subjected to a high impact on a side thereof (hereinafter referred to as “in the event of side impact”), a side door or a pillar may be deformed inwardly in a vehicle width direction due to the impact load in the event of side impact, and a door trim or a pillar trim forming an inner wall of a passenger compartment may come into the passenger compartment and come in direct contact with an occupant. Moreover, an inward external force in the vehicle width direction is applied by the impact load in the event of side impact, and an occupant seated on a seat may break through a seat belt restraint away outward in the vehicle width direction. In order to address such a situation, occupant protection apparatuses including a side airbag device that is deployed near an inner wall of a passenger compartment in the event of side impact and a seat belt device have been proposed.
For example, Japanese Patent Application Laid Open (JP-A) No. H4-50052 discloses an airbag device provided on a side face of a seat back facing a side door as an occupant protection apparatus in the event of side impact. Specifically, the airbag device of JP-A No. H4-50052 forms a shock-absorbing part by deploying an airbag from the seat back toward the side door and also forms an occupant protection part by deploying an airbag from the seat back in a direction inclining toward the vehicle front. The airbag device of JP-A No. H4-50052 thus prevents deformation of the side door by absorbing the impact by the shock-absorbing part formed by the deployed airbag.
In addition, JP-A No. 2007-223524 discloses an airbag device provided for a buckle device disposed on aside of a seat to lock an end of a lap belt part included in a seat belt device. In the airbag device of JP-A No. 2007-223524, an airbag is deployed and inflated in a gap between a buckle of the buckle device, the lap belt part and a seat part of the seat. Specifically, in the airbag device of JP-A No. 2007-223524, the airbag is deployed from an upper part of the vehicle in a direction inclining toward the front. In addition, the airbag is inflated in the vertical direction to such an extent that the airbag presses the lap belt part upward and inflated in the width direction until the airbag comes in contact with a side of the lumbar of the occupant. Moreover, the airbag device of JP-A No. 2007-223524 eliminates loosening of the lap belt part and eliminates the gap between the lap belt part, the buckle and the seat part to increase restraint of the lap belt part to the occupant.
However, although JP-A No. H4-50052 considers the case where an inner wall of the passenger compartment comes into the passenger compartment and comes in contact with the occupant as a result of the impact load at the time of side impact is considered, improvement is required for a case where an occupant breaks through the seat belt restraint away outward in the vehicle width direction. On the other hand, although JP-A No. 2007-223524 considers the case where an occupant breaks through the seat belt restraint away outward in the vehicle width direction, improvement is required for the case where an inner wall of the passenger compartment comes into the passenger compartment and comes in contact with the occupant. However, if it is attempted to overcome the drawbacks to be improved as described above in each of JP-A No. H4-50052 and JP-A No. 2007-223524, it is necessary to additionally provide another airbag device or newly improve the seat belt device.